CSS vendor prefixes were designed to help web developers by giving them a way to target CSS to specific browsers and use proposed standards before they were finalized. The idea was to move the web forward without rushing the CSS standards process. Unfortunately, it hasn’t always worked out that way. In fact, web developers fell in love with the -webkit- prefix and often forget that there are other prefixes as well: -o- for Opera, -moz- for Firefox and -ms- for Internet Explorer.

Now Opera says that to remain competitive it plans to support -webkit- in addition to its normal -o- prefix.

The problem, in Opera’s view, is that instead of writing code that will work in any web browser, some of even the largest sites on the web are coding exclusively for WebKit (the rendering engine that powers web browsers on the iPhone, iPad and Android phones). Web developers have, the argument goes, created the same sort of monoculture that used to exist around Internet Explorer, with websites proudly proclaiming they “work best in WebKit.”

In most cases Opera, Firefox and Internet Explorer support the same CSS features found in WebKit. The problem is that developers are only using the -webkit prefix, so only WebKit browsers render the effects. As a result, Opera, Firefox and IE look like less capable browsers even when they aren’t.

Opera web evangelist Bruce Lawson writes on the Opera development blog, “this leads to a reduced user experience on Opera and Firefox, which don’t receive the same shiny effects such as transitions, gradients and the like, even if the browser supported those effects” (emphasis in original).

Non-WebKit browser vendors first started talking about implementing the -webkit prefix earlier this year during a CSS Working Group meeting. Microsoft, Mozilla and Opera all said they felt the need to support -webkit, lest their users be relegated to an inferior browsing experience (because so many sites are using only the -webkit prefix).

While it’s not hard to understand Opera’s position, we’re disappointed to see Opera moving forward with this plan.

The very real danger is that if other browsers implement -webkit prefixes then the entire CSS standards effort will be broken.

Instead of coding against a single CSS specification developers will need to code against changing vendor prefixes. As CSS Working Group co-chair, Daniel Glazman, wrote when Opera first floated the idea, “I don’t think this is the right way. And this is the first time in this WG that we are proposing to do things that are not the right way.”

We at Webmonkey hope it’s obvious that building WebKit-only sites is a mistake. If you’re only interested in iOS users then take a tip from Instagram and build a native app. As Peter Linss, Hewlett-Packard’s CSS WG representative and co-chair of the working group, said at the earlier CSS WG meeting, “there’s no advantage to the web to have someone write a platform-specific website.” There’s no real advantage for the developer either, especially when an automated CSS prefixer can do all the work for you. So, if you’re using prefixes, we encourage you to take the time to add them all, test your site in as many browsers as possible and make sure your site works for everyone.